Marvell International Limited

Nxp Usa, Inc.

Wai Lau

Sai-Wang Tam

Alden C Wong

Xiaoang Li

Sudhir Srinivasa

Randy Tsang

Yui Lin

Ovidiu Carnu

Yuan Lu

Donghong Cui

Sridhar Reddy Narravula

Alireza Razzaghi

Amir Ghaffari

Timothy Loo

Tian Liu

A cancellation circuit includes a limiter connected to an output of a first transmitter power amplifier that converts in input sinewave to a digital square wave and a digital to time converter (DTC) connected to the limiter. A RF digital to RF converter is connected to the DTC that converts the digital square wave input into an analog RF output. A cancellation amplifier with an input receives an output from the RF digital to RF converter and has an output connected to an output of a second transmitter power amplifier. The cancellation amplifier produces a cancellation signal to cancel an interference signal at the output of the second transmitter power amplifier from the output of the first transmitter power amplifier. A power detector is connected to the output of the second power amplifier that produces a power value detected at the output of the second power amplifier.

Cancellation circuit using digital to time converter

Radio-frequency front-end circuitry includes an output terminal, a receive amplifier controllably coupled to the output terminal, at least one transmit amplifier controllably inductively coupled to the output terminal, and at least one impedance element controllably coupled between ground and one of the at least one transmit amplifier to reduce degradation of output of the radio-frequency front-end circuitry when the at least one transmit amplifier is not in use. In differential signaling, there is an impedance element between ground and each pole of the differential signal. A second transmit amplifier may generate second transmit signals and harmonics of the second transmit signals, and the second transmit amplifier may be switchably connected to the output of a first transmit amplifier so that output of the second transmit amplifier is filtered by the one of the first transmit amplifier. The transmit amplifiers may include a WiFi power amplifier and a BLUETOOTH&#xae; power amplifier.

Radio-frequency front end with power amplifier detuning to reduce output degradation

Bias current generator circuitry includes a first current source having a first temperature sensitivity characteristic, a second current source having a second temperature sensitivity characteristic, and temperature-sensitive control circuitry configured to select, as an output of the bias current generator circuitry, an output of the first current source when circuitry temperature is in a first temperature range, and an output of the second current source when circuitry temperature is in a second temperature range. In an example, the first temperature sensitivity characteristic is temperature independence and the second temperature sensitivity characteristic is proportionality to temperature. The control circuitry includes a third current source having the first temperature sensitivity characteristic, a fourth current source having the second temperature sensitivity characteristic. Comparison circuitry is configured to compare an output of the third current source and an output of the fourth current source, to select between the first and second current sources.

Bias current generator having blended temperature response

An apparatus includes a current-to-voltage converter configured to convert first and second currents into first and second input voltages and provide the first and second input voltages to first and second nodes, respectively, and a current difference determination circuit configured to determine a difference between the first and second currents based on a difference between the first and second input voltages. A method includes converting first and second currents into first and second input voltages to output the first and second input voltages to first and second nodes, respectively, and determining a difference between the first and second currents based on a difference between the first and second input voltages.

Current comparator

Growing community of inventors

San Jose, CA, United States of America

Wai Lau